| 摘要 |
A processor for a radio receiver is adapted to process direct sequence spread spectrum (DS-SS signals), and includes a demodulator, digitiser, correlator, and chip-matched filter (CMF) wherein the digitiser sample rate is selected to take a plurality of samples of each incoming chip at differing points thereon compared to sample points on an adjacent chip and to sample the chip at a non-integer multiple of the chip rate, wherein the CMF is arranged to filter the output of the digitiser. A sample selection unit is arranged to select a single sample from the CMF for input to each tap of the correlator, the selected sample being chosen as that nearest in time to a desired ideal time in relation to a timing reference point on the chip. An improved correlation function results, leading to better tracking performance. |
